In the field of X-ray security check, a X-ray vehicle check system consists of a X-ray imaging sub-system, a scanning control sub-system, an operation check sub-system and an radiation security sub-system, wherein the X-ray imaging sub-system is the core of the whole system and is composed of a radiation source, detectors and a data acquisition and control module, and the X-ray imaging sub-system is configured to generate X-ray transmitting and/or scattering image. When a checked container/vehicle is scanned, the radiation source generates high-energy X-ray pulses transmitting the checked goods, and an array of high-sensitivity detectors receives X-rays and converts them into output signal, and a series of digital image signals are generated in real-time by the data acquisition and control module. When the whole scanning procedure is completed, the system automatically generates a complete image of the checked vehicle.
A conventional container/vehicle quick check system adopts an accelerator as the radiation source for scan imaging of the container. It is found out in the field of X-ray security check that, security check efficiency will be largely improved if a driver can drive the vehicle through the X-ray check system instead of performing a “park—get off—scan—drive” procedure. However, in order to ensure penetration power and image quality, X-rays output by the radiation source have relatively high dose rates. However, in most commercial working environment, when a high-dose X-ray source is used for imaging, the ray dose accumulated in the driver during such scanning process will be at an unacceptable level. As specified in ANSI/HPS N43.17-2009, the dose received by the driver one time cannot exceed 0.25 μSv. Therefore, as shown in FIG. 1, in order to guarantee radiation security of the driver, it is necessary to dodge the cab part and start high-dose X-ray scanning behind the cab and at a safe distance away from the cab, so as to avoid the out-of-limit X-ray dose for the driver which is caused by the scattering generated during high-dose X-ray scanning of the radiation source which starts immediately after the driver is dodged. As for a container vehicle, there is an enough interval between its cab and the rear containers, and thus, such a method can be employed without losing scanning information of the containers. However, in addition to checking containers in a harbor, the current vehicle quick check system is increasingly applied to land border vehicle check and vehicle security check in some important places. In such application scenarios, in addition to container trucks, common vans, minivans, and even large buses need to be checked. For a van, its rear carriage is very close to its front cab, so that if a high-dose X-ray scanning starts after leaving an interval as safe distance, a part of the carriage behind the cab will have no scanning image. For other types of vehicles which need to be checked, such as minivans, large buses, a part of vehicle body will have no scanning images either. There exists a relatively high risk of supervision for customs smuggling check or security check.